Whole-body Low-dose CT Research Articles

Trabecular Attenuation of L1 in Adult Patients with Multiple Myeloma: An Observational Study on Low-Dose CT Images.

The aim of this study was to evaluate the impact of trabecular attenuation of the L1 vertebral body in low-dose CT in adult patients with multiple myeloma (MM), smoldering multiple myeloma (SMM), and monoclonal gammopathy of undetermined significance (MGUS). The study population consisted of 22 patients with MGUS and 51 consecutive patients with newly diagnosed MM (SMM, n = 21; symptomatic MM, n = 36). CT scans were conducted using a 128-slice CT scanner (Somatom go.Top, Siemens, Munich, Germany). Low-dose whole-body CT scans were performed at a single time point for each patient. Trabecular bone density values were obtained by defining regions of interest on non-contrast images at the level of L1 vertebra. A threshold of p = 0.05 was applied to determine statistical significance. The median Hounsfield unit (HU) value in patients with MGUS, SMM, and MM was 148 HU (range 81-190), 130 HU (range 93-193), and 92 HU (range 26-190), respectively, with a statistically significant difference between the groups (p = 0.0015). Patients with HU values ≤ 92 had lower progression-free survival with statistically significant differences compared to the group with HU values > 92 (p < 0.0499). This is the earliest evidence of the importance of evaluating L1 attenuation values in low-dose CT images in patients with MGUS, SMM, and MM. Further prospective studies could contribute to reinforcing these results and exploring the clinical applicability and generalization of L1 attenuation values in low-dose whole-body CT scans in routine clinical practice.

Abstract PO5-05-13: Clinical utility of whole body low dose computed tomography for detecting bone metastasis in breast cancer patients: A cross sectional study

Abstract Clinical utility of Whole Body Low Dose CT scan for detecting bone metastasis in Breast cancer patients: A cross sectional study Background: Skeletal scintigraphy (Bone scan) is the imaging of choice to detect bone metastasis in locally advanced and metastatic breast cancer patients. Nuclear medicine facilities are however limited in their availability. As an alternative diagnostic modality to bone scan, we studied the diagnostic capability of Whole-Body Low Dose CT (WBLDCT) scan for detection of bone metastasis in these patients. Materials and Method: This cross-sectional study was conducted from November 2021 to May 2023 at a tertiary healthcare center in India with an aim to study the clinical applicability of whole-body low dose computed tomography scan for detecting bone metastasis in patients with breast cancer. Breast cancer patients with primary tumor measuring 5cm or more, pathologically proven axillary lymph node metastasis, Stage III/IV disease, symptoms attributable to metastasis and suspected disease recurrence were included. All patients underwent WBLDCT and Bone scan within a period of about 2 weeks. WBLDCT was done during the same time as conventional dose CT scan was being done as part of metastatic workup. WBLDCT acquisition protocol was set in CT scan machine by modulating the technical parameters like Care dose 4D-automated, Care kV semi, rotation time &amp; noise index. The image analysis was performed by Radiologist and Nuclear medicine experts in a blinded fashion. Data was recorded in MS Excel sheet. Sensitivity, specificity, positive and negative predicative value, and concordance rates were calculated using SPSS software ver 25.0. Agreement amongst WBLDCT and Bone scan was calculated using Inter-rater agreement. p value &amp;lt; 0.05 was taken as significant. Results: 110 patients were enrolled in this study. The mean age of participants was 48.5 years and three fourth had stage III disease at presentation. Estrogen receptor positive disease was seen in 43.64% participants while 30% were triple negative. Her2neu positive disease was seen in 27.27% patients. Bone scan couldn’t be done in 03 patients who deferred treatment (these had no bone metastasis on WBLDCT). Both bone scan and WBLDCT detected bone metastasis in 19 patients. Bone scan picked up additional metastasis in three patients which were missed on WBLDCT. WBLDCT detected bone metastasis additionally in three patients which were not detected on Bone scan. Multiple lesions were most seen in vertebrae in 38.5% and 28.6% on bone scan and WBLDCT respectively. The sensitivity and specificity of WBLDCT for detection of bone metastasis was 86.36% and 96.47% respectively. The concordance rate between Bone scan and WBLDCT scan was 94.39% with an Inter-rater Kappa(k) quotient for agreement of 0.828 (p&amp;lt; 0.0001). Conclusion: WBLDCT scan has comparable diagnostic capability to skeletal scintigraphy in detecting bone metastasis in breast cancer and may be a useful alternative specially in resource limited settings. Table 1: Sensitivity, specificity, positive predictive value and negative predictive value of WBLDCT for detection of metastasis Variables Values Sensitivity (95% CI) 86.36% Specificity (95% CI) 96.47% AUC (95% CI) 0.91 Positive Predictive Value (95% CI) 86.36% Negative Predictive Value (95% CI) 96.47% Diagnostic accuracy 94.39% Inter-rater agreement (kappa) 0.828 Citation Format: Lipton Mitra, Suhani Suhani, Ankur Goyal, Rakesh Kumar, Mohit Joshi, Hemanga Bhattacharjee, Haresh KP, Raju Sharma, Rajinder Parshad. Clinical utility of whole body low dose computed tomography for detecting bone metastasis in breast cancer patients: A cross sectional study [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO5-05-13.

Quantitative assessment of bone marrow infiltration and characterization of tumor burden using dual-layer spectral CT in patients with multiple myeloma.

The aim of the study was to evaluate whether virtual calcium subtraction (VNCa) image extracted from dual-layer spectral CT could estimate bone marrow (BM) infiltration with MRI as the reference standard and characterize tumor burden in patients with multiple myeloma (MM). Forty-seven patients with newly diagnosed MM were retrospectively enrolled. They had undergone whole-body low-dose dual-layer spectral CT (DLCT) and whole-body MRI within one week. VNCa images with calcium-suppressed (CaSupp) indices ranging from 25 to 95 at an interval of 10 and apparent diffusion coefficient (ADC) maps were quantitatively analyzed on vertebral bodies L1-L5 at the central slice of images. The optimal combination was selected by correlation analysis between CT numbers and ADC values. Then, it was used to characterize tumor burden by correlation analysis and receiver operating characteristic (ROC) curves analysis, including plasma cell infiltration rate (PCIR), high serum-free light chains (SFLC) ratio and the high-risk cytogenetic (HRC) status. The most significant quantitative correlation between CT numbers of VNCa images and ADC values could be found at CaSupp index 85 for averaged L1-L5 (r = 0.612, p < 0.001). It allowed quantitative evaluation of PCIR (r = 0.835, p < 0.001). It could also anticipate high SFLC ratio and the HRC status with area under the curve (AUC) of 0.876 and 0.760, respectively. The VNCa measurements of averaged L1-L5 showed the highest correlation with ADC at CaSupp index 85. It could therefore be used as additional imaging biomarker for non-invasive assessment of tumor burden if ADC is not feasible.

Imaging Practices in Patients with Plasma Cell Dyscrasias across the Asian Myeloma Network - Survey Results and Recommendations

Objective: Though consensus imaging guidelines from International Myeloma Working Group (IMWG) for the detection of bone and marrow lesions in plasma cell disorders are available, significant challenges remain in adoption of such guidelines in Asia. The objectives of this study were: (1) To survey, document and evaluate the imaging practices in plasma cell disorders across Asian Myeloma Network (AMN) member countries and (2) To identify factors influencing decision making in choosing the imaging modalities with a view to explore barriers and solutions. Methods: AMN Members from China, Japan, Republic of Korea, Malaysia, Taiwan, Thailand and Singapore participated in the bone imaging work group organized during the 6 th AMN summit in Sep 2022 at Singapore. Members discussed the prevailing bone imaging practices and how they relate to IMWG recommendations. A bone imaging survey questionnaire was then designed from these inputs and circulated to the wider AMN members. The results were collated and analyzed. Results &amp; Discussion: Forty-Eight responses were received from 37 public tertiary or academic hospitals, 9 from peripheral hospitals and 2 from private hospitals. With regards to precursor plasma cell disorders (MGUS / SMM Vs MM), the preferred imaging modalities for screening bone disease in patients suspected to have myeloma were skeletal survey (SS) (n=13, 27%), whole body low dose CT (WBLDCT) (n=13, 27%) and PET CT (n=14, 29%). The preferred mode for 1 st line imaging in patients with confirmed newly diagnosed myeloma was PET CT (n=25, 52%) however half of the participants opted for SS (n=7, 15%), WBLDCT (n=10, 21%) and whole-body MRI (WBMRI) (n=6, 13%). Using SS prior to myeloma treatment or to differentiate SMM from MM can lead to significant under-recognition of bone disease and its consequences on disease classification and impact on treatment. Centers which are performing SS but have compatible CT scanners could consider adopting a WBLDCT protocol which is relatively easy and cost-effective. Preferred first-line imaging options for Plasmacytoma and EMD were largely appropriate with 70-80% opting for PET CT or WBMRI. However, for response assessment in MM, the majority chose PET CT or MRI, some members or institutions are still using SS or WBLDCT. While CT scan might be able to show some sclerotic healing or a worsening lytic component, SS is unlikely to provide any useful information in this situation and should be avoided to reduce unnecessary radiation exposure. At least 5 participants indicated that they do not perform routine imaging in newly diagnosed multiple myeloma for disease response assessment. Barriers identified in establishing cross-sectional imaging service include lack of financial reimbursement or subsidies, equipment, or personnel availability like the presence of nuclear medicine or specialized radiologists. While 81% of participants reported financial reimbursements for SS, only about 50% reported subsidies for WBMRI (56%) or PET CT (54%). One shortfall of this study is that our survey was conducted within the framework of an academic myeloma community and while it may not be representative of the practices in the whole region, the use of sub-optimal imaging like SS underlines the need for standardisation and adoption of cross-sectional imaging. Conclusion: There is considerable variation in imaging practices for precursor plasma cell disorders and myeloma in centres across Asia. Resource limitation, specifically lack of financial subsidies for imaging, infrastructure or lack of experienced personnel all remain as major challenges in the implementation of standardized imaging practice for myeloma in Asia. However increased adoption of cross-sectional imaging in large tertiary centres are to be welcomed and suggest that in these centres, practices do closely mirror those in the IMWG recommendations. Increasing awareness of the potentially catastrophic nature of myeloma bone disease and the preventive role that cross sectional imaging could provide, representations and dialogues with healthcare funders to this aspect of myeloma care, incorporation of low dose CT protocols to help move away from skeletal survey in centres which already have CT scanners as well as myeloma patient and Physician education could all be useful tools to enhance bone imaging standards in Asia.

Identification of focal lesion characteristics in MRI which indicate presence of corresponding osteolytic lesion in CT in patients with multiple myeloma.

The presence of bone marrow focal lesions and osteolytic lesions in patients with multiple myeloma (MM) is of high prognostic significance for their individual outcome. It is not known yet why some focal lesions seen in MRI, reflecting localized bone marrow infiltration of myeloma cells, remain non-lytic, whereas others are associated with destruction of mineralized bone. In this study, we analyzed MRI characteristics of manually segmented focal lesions in MM patients to identify possible features that might discriminate lytic and non-lytic lesions. The initial cohort included a total of 140 patients with different stages of MM who had undergone both whole-body MRI and whole-body low-dose CT within 30 days, and of which 29 satisfied the inclusion criteria for this study. Focal lesions in MRI and corresponding osteolytic areas in CT were segmented manually. Analysis of the lesions included volume, location and first order texture features analysis. There were significantly more lytic lesions in the axial skeleton than in the appendicular skeleton (p = 0.037). Out of 926 focal lesions in the axial skeleton seen on MRI, 544 (59.3 %) were osteolytic. Analysis of volume and first order texture features showed differences in texture and volume between focal lesions in MRI with and without local bone destruction in CT, but these findings were not statistically significant. Neither morphological imaging characteristics like size and location nor first order texture features could predict whether focal lesions seen in MRI would exhibit corresponding bone destruction in CT. Studies performing biopsies of such lesions are ongoing.

P-065 Whole body low dose CT (WBLDCT), as initial imaging modality for newly diagnosed multiple myeloma patients: experience from a teritary care center in North India

P-065 Whole body low dose CT (WBLDCT), as initial imaging modality for newly diagnosed multiple myeloma patients: experience from a teritary care center in North India

Assessing Osteolytic Lesion Size on Sequential CT Scans Is a Reliable Study Endpoint for Bone Remineralization in Newly Diagnosed Multiple Myeloma.

Multiple myeloma (MM) frequently induces persisting osteolytic manifestations despite hematologic treatment response. This study aimed to establish a biometrically valid study endpoint for bone remineralization through quantitative and qualitative analyses in sequential CT scans. Twenty patients (seven women, 58 ± 8 years) with newly diagnosed MM received standardized induction therapy comprising the anti-SLAMF7 antibody elotuzumab, carfilzomib, lenalidomide, and dexamethasone (E-KRd). All patients underwent whole-body low-dose CT scans before and after six cycles of E-KRd. Two radiologists independently recorded osteolytic lesion sizes, as well as the presence of cortical destruction, pathologic fractures, rim and trabecular sclerosis. Bland-Altman analyses and Krippendorff's α were employed to assess inter-reader reliability, which was high for lesion size measurement (standard error 1.2 mm) and all qualitative criteria assessed (α ≥ 0.74). After six cycles of E-KRd induction, osteolytic lesion size decreased by 22% (p < 0.001). While lesion size response did not correlate with the initial lesion size at baseline imaging (Pearson's r = 0.144), logistic regression analysis revealed that the majority of responding osteolyses exhibited trabecular sclerosis (p < 0.001). The sum of osteolytic lesion sizes on sequential CT scans defines a reliable study endpoint to characterize bone remineralization. Patient level response is strongly associated with the presence of trabecular sclerosis.

Whole-body low-dose CT can be of value in prostate cancer decision-making: a retrospective study on 601 patients

ObjectivesTo evaluate the diagnostic value of whole-body low-dose computed tomography (CT) to detect bone metastasis in prostate cancer (PCa) patients and its possible utility in therapeutic decision-making. Also, to determine the valuable CT features for lesion characterisation.MethodsThis IRB-approved retrospective study reviewed PCa patients who underwent 68Ga-PSMA PET/CT in our centre from March 2017 to August 2022. Two board-certified radiologists and one nuclear medicine specialist reported all whole-body low-dose CT scans separately, unaware of the 68Ga-PSMA-PET results. The per-lesion and per-patient diagnostic performances were calculated. Also, the significance of CT features was evaluated. Moreover, the inter-observer agreement was analysed. A two-tailed p value < 0.05 was considered significant.ResultsFrom 727 reviewed PCa patients, 601 (mean age = 68.7 ± 8.1) were found to be eligible, including 211 (35.1%) referrals for initial staging and 390 (64.9%) for evaluating the extent of the disease after biochemical recurrence. Per-patient diagnostic analysis for three reviewers showed 81.0–89.4% sensitivity and 96.6–98.5% specificity in detecting osteo-metastasis. It was able to correctly detect high-burden disease based on both CHAARTED and LATITUDE criteria. Regarding the value of underlying CT features, size > 1 cm, ill-defined borders, presence of soft-tissue component, and cortical destruction were statistically in favour of metastasis. Also, Hu > 900 was in favour of benign entities with 93% specificity.ConclusionsAlthough not as accurate as 68Ga-PSMA PET/CT, whole-body low-dose CT might precisely classify PCa patients considering therapeutic decision-making. Additionally, we proposed diagnostic CT features that could help radiologists with better characterisation of the detected lesions.Critical relevance statementThe whole-body low-dose CT can be considered valuable in the clinical decision-making of prostate cancer patients. This modality may obviate performing multiple imaging sessions and high-cost scans in patients diagnosed with the high-burden disease.Graphical abstract

Whole-body low-dose computed tomography in primary patients with multiple myeloma

Imaging of bone lesions has an important role in diagnosis of multiple myeloma (MM) and evaluating the response to treatment. Computed tomography scan (CT) allows to detect osteolysis, plasmacytoma and the risk of fractures with high sensitivity. In the National Research Center For Hematologysince 2014 all patients with MM are diagnosed with the whole-body low-dose CT.The aim of the study was to demonstrate the sensitivity of the whole-body low-dose CT and to characterize localization, number and size of bone lesions in primary MM patients.Materials and methods. 50 patients with newly diagnosed MM were enrolled in the study. The diagnosis was established in accordance with international diagnostic criteria. All patients received the whole-body low-dose CT. According to the Durie-Salmon and ISS staging systems 62% and 66% of patients had stage III, respectively.Results. 96% of MM patients had bone lesions. In 30% of patients, bone involvement was the only criterion for CRAB. Pelvic bone lesions was most often diagnosed (92%). The destruction of the long bones of the arms and legs were most rarely detected (42% of patients) and mostly small. The presence of intraosseous plasmocytoma was noted in 40% of cases.Conclusion. The whole-body low dose CT was found to be the most sensitive modality for detection osteolytic bone lesions. Low-dose CT is available in MM case with bone disease only, for establish symptomatic stage. This patients require immedate antimyeloma treatment.

BMI and Waist Circumference in Patients with Multiple Myeloma.

Context: Cancer is associated with many risk factors, including obesity. Specifically, abdominal obesity is linked to metabolic syndrome and is quantified by waist circumference (WC). Compared to WC, body mass index (BMI) is more accessible in the office to assess a patient's overall body fat composition. With preexisting computed tomography (CT) scans in multiple myeloma (MM) patients, WC can be obtained quickly and accurately as a potential prognostic biomarker. Objective: To determine if there is a correlation between BMI and WC in MM patients. Study Design and Analysis: This is a retrospective cohort study using preexisting CT scans of MM patients. Demographic information including age, sex, race, and BMI was gathered. The WC was obtained using Aquarius iNtuition software version 4.4.12. To standardize the CT scan measurements, slices were taken at the L3 vertebra with both transverse processes visible. Setting/Dataset: An academic midwestern healthcare system. Population Studied: A cohort of MM patients with CT scans. Intervention/Instrument: The scans were analyzed with Aquarius iNtuition. Outcome Measures: Average BMI and WC, as well as the correlation between BMI and WC. Results: This study includes 71 MM patients (37 women and 34 men) who had a whole-body low-dose CT scan. The average BMI was in the overweight range for both women and men at 28.7 and 28.8, respectively. Notably, the average WC was 39.4 inches for women and 41.9 inches in men, meeting one of the criteria for metabolic syndrome (>35 inches in women and >40 inches in men). BMI and WC were significantly correlated in both men and women (p <0.001). Conclusions: This is a retrospective analysis of BMI and WC in a cohort of MM patients. Traditionally, BMI has been used to quickly assess the body fat composition of patients. However, WC is a more accurate and readily accessible tool in patients with a CT scan. This measurement is strongly tied to metabolic syndrome and is part of the diagnostic criteria. We found that BMI and WC were significantly correlated in this cohort. Further follow-up is needed with a larger sample size and over a longer period. As body composition in this cohort has not been previously studied, further analyses may provide more biomarkers to aid in disease management.

Density of the Spleen in Low-Dose CT Scans Is Associated with High-Risk Disease Features and Shorter Survival in Newly Diagnosed Multiple Myeloma Patients

Introduction Whole body low-dose computed tomography (WBLDCT) is standard of care in the diagnostic work-up of suspected multiple myeloma. While the focus of clinical routine evaluation lies on the detection of osteolytic lesions or extramedullary myeloma manifestations, the entire informative capacity of WBLDCT scans seems underestimated. Here, the analysis of non-focal signal alterations might provide further diagnostic insights, and a recent study by Terao et al. described tumor-burden dependent loss of the splenic signal in diffusion-weighted MRI in newly diagnosed myeloma (NDMM) patients. However, due to limited availability of MRI, most NDMM patients receive WBLDCT at initial diagnostic work-up. Therefore, we asked if non-focal signal alterations of the spleen in WBLDCT scans (i.e., radiographic tissue density of the organ) in NDMM patients might correlate with disease characteristics, cytogenetics and clinical outcomes. Methods In this retrospective analysis, we screened clinical records of NDMM patients diagnosed and treated at our institution (LMU University Hospital Munich, Germany) between 01/2010 and 12/2020. Clinical and laboratory data from initial diagnosis until first relapse were integrated with segmentation analyses of WBLDCT scans taken within 90 days before diagnosis. Plasma cell dyscrasias others than MM as well as cases with CT scans taken >90 days before diagnosis or CT scans containing contrast media were excluded. Results A total of 231 consecutively treated NDMM patients were included with a median age of 66 years (range 25-89). Cytogenetic analyses were available in 177 (77%) patients of which 38 had high-risk (HR) aberrations including t(4;14), t(14;16) and del(17p). In 44 (19%) of patients a gain(1q) was found. Patients were classified according to ISS and R-ISS: ISS-1 84 (43%), ISS-2 56 (28%), ISS-3 57 (29%) and R-ISS-1 38 (22%), R-ISS-2 119 (70%), R-ISS-3 13 (8%). Induction therapy consisted of a doublet regimen in 61 (26%), a triplet regimen in 167 (72%) and a quadruplet regimen in 3 (1%) patients. From the entire cohort, 141 (61%) patients received high-dose melphalan and autologous stem cell transplantation (auto-SCT), and 46 (20%) patients underwent tandem auto-SCT. Maintenance therapy after auto-SCT was applied to 49 (35% of auto-SCT) patients. Spleen density gradually increased with ISS and R-ISS stages. Thus, ISS3 and R-ISS3 displayed a significantly increased spleen density compared to ISS1 and R-ISS1 patients (ISS3 40.7 HU vs. ISS1 35 HU, p=0.003; R-ISS3 45.4 vs. R-ISS1 32.5 HU, p=0.004, Fig. 1A). We further found spleen density to be significantly higher in patients with HR cytogenetics (HR vs SR HU, p=0.03), in particular with t(4;14) (p=0.04), but not with del(17p), t(14;16) or gain(1q). Moreover, it positively correlated with serum lambda light chain levels in patients with lambda paraproteinemia (r = 0.26, p = 0.02), but not with kappa light chain or immunoglobulin levels. Based on an optimal log-rank test separation algorithm, NDMM patients with a spleen density of > 53.5 HU (Spleenhigh) had a shorter survival compared to Spleenlow patients (median PFS: 18.9 vs 32.1 months, p=0.01, Fig. 1B; median OS: not reached, p=0.02). PFS and OS differences were similar in subgroup analysis of transplant-eligible (PFS: p=0.08; OS: p=0.04) and transplant-ineligible patients (PFS: p=0.02, OS: p=0.04). In multivariate cox regression analyses including Spleenhigh/low and R-ISS stages, spleen density remained an independent factor for shorter survival (HRPFS 2.45, 95%CI 1.21-4.49, p=0.007; HROS 3.24, 95%CI 1.06-8.23, p=0.02). Conclusion Our data suggest that high density of the splenic tissue in WBLDCT is associated with high-risk features and inferior survival of NDMM patients. Increased cell numbers or deposition of light chains within the spleen might represent modes of action. If validated in future prospective studies, spleen WBLDCT density may complement existing risk-stratification tools. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Photon-counting Detector CT with Deep Learning Noise Reduction to Detect Multiple Myeloma.

Background Photon-counting detector (PCD) CT and deep learning noise reduction may improve spatial resolution at lower radiation doses compared with energy-integrating detector (EID) CT. Purpose To demonstrate the diagnostic impact of improved spatial resolution in whole-body low-dose CT scans for viewing multiple myeloma by using PCD CT with deep learning denoising compared with conventional EID CT. Materials and Methods Between April and July 2021, adult participants who underwent a whole-body EID CT scan were prospectively enrolled and scanned with a PCD CT system in ultra-high-resolution mode at matched radiation dose (8 mSv for an average adult) at an academic medical center. EID CT and PCD CT images were reconstructed with Br44 and Br64 kernels at 2-mm section thickness. PCD CT images were also reconstructed with Br44 and Br76 kernels at 0.6-mm section thickness. The thinner PCD CT images were denoised by using a convolutional neural network. Image quality was objectively quantified in two phantoms and a randomly selected subset of participants (10 participants; median age, 63.5 years; five men). Two radiologists scored PCD CT images relative to EID CT by using a five-point Likert scale to detect findings reflecting multiple myeloma. The scoring for the matched reconstruction series was blinded to scanner type. Reader-averaged scores were tested with the null hypothesis of equivalent visualization between EID and PCD. Results Twenty-seven participants (median age, 68 years; IQR, 61-72 years; 16 men) were included. The blinded assessment of 2-mm images demonstrated improvement in viewing lytic lesions, intramedullary lesions, fatty metamorphosis, and pathologic fractures for PCD CT versus EID CT (P < .05 for all comparisons). The 0.6-mm PCD CT images with convolutional neural network denoising also demonstrated improvement in viewing all four pathologic abnormalities and detected one or more lytic lesions in 21 of 27 participants compared with the 2-mm EID CT images (P < .001). Conclusion Ultra-high-resolution photon-counting detector CT improved the visibility of multiple myeloma lesions relative to energy-integrating detector CT. © RSNA, 2022 Online supplemental material is available for this article.

A deep learning algorithm for detecting lytic bone lesions of multiple myeloma on CT.

Whole-body low-dose CT is the recommended initial imaging modality to evaluate bone destruction as a result of multiple myeloma. Accurate interpretation of these scans to detect small lytic bone lesions is time intensive. A functional deep learning) algorithm to detect lytic lesions on CTs could improve the value of these CTs for myeloma imaging. Our objectives were to develop a DL algorithm and determine its performance at detecting lytic lesions of multiple myeloma. Axial slices (2-mm section thickness) from whole-body low-dose CT scans of subjects with biochemically confirmed plasma cell dyscrasias were included in the study. Data were split into train and test sets at the patient level targeting a 90%/10% split. Two musculoskeletal radiologists annotated lytic lesions on the images with bounding boxes. Subsequently, we developed a two-step deep learning model comprising bone segmentation followed by lesion detection. Unet and "You Look Only Once" (YOLO) models were used as bone segmentation and lesion detection algorithms, respectively. Diagnostic performance was determined using the area under the receiver operating characteristic curve (AUROC). Forty whole-body low-dose CTs from 40 subjects yielded 2193 image slices. A total of 5640 lytic lesions were annotated. The two-step model achieved a sensitivity of 91.6% and a specificity of 84.6%. Lesion detection AUROC was 90.4%. We developed a deep learning model that detects lytic bone lesions of multiple myeloma on whole-body low-dose CTs with high performance. External validation is required prior to widespread adoption in clinical practice.

Progress of modern imaging modalities in multiple myeloma.

Multiple myeloma (MM) is an incurable hematological malignancy, but treatment advances made in the last two decades have markedly improved its prognosis. Imaging has played a particularly important role in the management of myeloma. Whole-body low-dose computed tomography (WBLDCT) is replacing conventional skeletal survey by whole-body X-rays. In addition, magnetic resonance imaging (MRI) and positron-emission tomography/computed tomography (PET/CT) have become important imaging modalities not only for MM diagnosis but also for assessment of myeloma cell infiltration, extramedullary disease, treatment efficacy, and prognosis. However, there is room to improve their accuracy and specificity for assessment of treatment response, tumor volume, and residual disease. This review introduces novel diagnostic techniques, such as WBLDCT, MRI, and PET/CT, discusses their contribution to MM care, and lists areas for future research.

Modern imaging techniques for monitoring patients with multiple myeloma.

Bone disease is a serious problem for many patients, often causing pathological bone fractures. A spinal collapse is a condition that affects the quality of life. It is the most frequent feature of multiple myeloma (MM), used in establishing the diagnosis and the need to start treatment. Because of these complications, imaging plays a vital role in the diagnosis and workup of myeloma patients. For many years, conventional radiography has been considered the gold standard for detecting bone lesions. The main reasons are the wide availability, low cost, the relatively low radiation dose and the ability of this imaging method to cover the entire bone system. Because of its incapacity to evaluate the response to therapy, more sophisticated techniques such as whole-body low-dose computed tomography (WBLDCT), whole-body magnetic resonance imaging, and 18F-fluorodeoxyglucose-positron emission tomography/computed tomography (PET/CT) are used. In this review, some of the advantages, indications and applications of the three techniques in managing patients with MM will be discussed. The European Myeloma Network guidelines have recommended WBLDCT as the imaging modality of choice for the initial assessment of MM-related lytic bone lesions. Magnetic resonance imaging is the gold-standard imaging modality for the detection of bone marrow involvement. One of the modern imaging methods and PET/CT can provide valuable prognostic data and is the preferred technique for assessing response to therapy.

A prospective study of Skeletal survey versus Low-dose whole-body CT for Osteolytic lesions in Multiple Myeloma.

To compare WBLDCT to CSS for identifying progressive bone disease in MM in a prospective setting. Ninety-six patients with MM at Odense University Hospital and Stavanger Hospital were followed for up to four years. Patients were scanned with WBLDCT and CSS every year for the first two years and every six months thereafter or at suspicion of progression. Nineteen cases of progressive bone disease were found using WBLDCT vs eight cases using CSS (p<0.001). All cases of progressive bone disease using CSS were also identified by WBLDCT. Progression not found by CSS was primarily in the spine, sternum, and pelvis. Of the 19 cases, five patients had progressive bone disease only without other criteria for clinical progression. WBLDCT consistently identified more bone lesions per patient, 8.2 CI(6.8;9.6) vs CSS, 3.6 CI(2.7;4.5). WBLDCT outperformed CSS for finding progressive bone disease and osteolytic lesions. More new lesions were found during follow-up by WBLDCT than CSS. Using CSS for lytic lesions will underestimate progression rates. Our data offer prospective evidence for the current recommendation using WBLDCT for skeletal evaluations in patients with multiple myeloma.

Whole-Body Low-Dose Multidetector-Row CT in Multiple Myeloma: Guidance in Performing, Observing, and Interpreting the Imaging Findings.

Multiple myeloma is a hematological malignancy of plasma cells usually detected due to various bone abnormalities on imaging and rare extraosseous abnormalities. The traditional approach for disease detection was based on plain radiographs, showing typical lytic lesions. Still, this technique has many limitations in terms of diagnosis and assessment of response to treatment. The new approach to assess osteolytic lesions in patients newly diagnosed with multiple myeloma is based on total-body low-dose CT. The purpose of this paper is to suggest a guide for radiologists in performing and evaluating a total-body low-dose CT in patients with multiple myeloma, both newly-diagnosed and in follow-up (pre and post treatment).

Ultra-Low-Dose Whole-Body Computed Tomography Protocol Optimization for Patients With Plasma Cell Disorders: Diagnostic Accuracy and Effective Dose Analysis From a Reference Center.

BackgroundThe whole-body low-dose CT (WBLDCT) is the first-choice imaging technique in patients with suspected plasma cell disorder to assess the presence of osteolytic lesions. We investigated the performances of an optimized protocol, evaluating diagnostic accuracy and effective patient dose reduction using a latest generation scanner.Methods and MaterialsRetrospective study on 212 patients with plasma cell disorders performed on a 256-row CT scanner. First, WBLDCT examinations were performed using a reference protocol with acquisition parameters obtained from literature. A phantom study was performed for protocol optimization for subsequent exams to minimize dose while maintaining optimal diagnostic accuracy. Images were analyzed by three readers to evaluate image quality and to detect lesions. Effective doses (E) were evaluated for each patient considering the patient dimensions and the tube current modulation.ResultsA similar, very good image quality was observed for both protocols by all readers with a good agreement at repeated measures ANOVA test (p>0.05). An excellent inter-rater agreement for lesion detection was achieved obtaining high values of Fleiss’ kappa for all the districts considered (p<0.001). The optimized protocol resulted in a 56% reduction of median DLP (151) mGycm, interquartile range (IQR) 128–188 mGycm vs. 345 mGycm, IQR 302–408 mGycm), of 60% of CTDIvol (2.2 mGy, IQR 1.9–2.7 mGy vs. 0.9 mGy, IQR 0.8–1.2 mGy). The median E value was about 2.6 mSv (IQR 1.7–3.5 mSv) for standard protocol and about 1.5 mSv (IQR 1.4–1.7 mSv) for the optimized one. Dose reduction was statistically significant with p<0.001.ConclusionsProtocol optimization makes ultra-low-dose WBLDCT feasible on latest generation CT scanners for patients with plasma cell disorders with effective doses inferior to conventional skeletal survey while maintaining excellent image quality and diagnostic accuracy. Dose reduction is crucial in such patients, as they are likely to undergo multiple whole-body CT scans during follow-up.

Prevalence of Smoldering Multiple Myeloma: Results from the Iceland Screens, Treats, or Prevents Multiple Myeloma (iStopMM) Study

Prevalence of Smoldering Multiple Myeloma: Results from the Iceland Screens, Treats, or Prevents Multiple Myeloma (iStopMM) Study

Oncologist perspective: role of imaging in myeloma.

With major advancements in treatments for multiple myeloma (MM), it is critical that we evaluate our methods for both diagnosing MM and monitoring its progression over time. Imaging methods, such as conventional skeletal x-ray, low-dose whole-body CT, MRI, and PET-CT, provide valuable information that influences our clinical decision-making. In this review, we will evaluate the role of these imaging techniques throughout the MM disease course, from diagnosis to follow-up after therapy, and also provide appropriate recommendations.